Jealousy is a destructive trait that often stems from insecurity and causes people to commit crimes like murder. The document discusses how jealousy led an 11-year-old boy to kill his infant brother because he was jealous of the attention the baby received. It also describes how a jealous teenager murdered his best friend after his ex-girlfriend left him for the friend. Lastly, it mentions a case where a woman was killed by acquaintances who were jealous of her financial success.